Voice over internet protocol (“VoIP”) communication systems allow the user of a device, such as a personal computer, to make calls across a computer network such as the Internet. These systems are beneficial to the user as they are often of significantly lower cost than fixed line or mobile networks. This may particularly be the case for long distance calls. To use VoIP, the user must install and execute client software on their device. The client software provides the VoIP connections as well as other functions such as registration and authentication. In addition to voice communication, the client may also provide video calling and instant messaging (“IM”).
One type of VoIP communication system uses a peer-to-peer (“P2P”) topology built on proprietary protocols. To enable access to a peer-to-peer system, the user must execute P2P client software provided by a P2P software provider on their computer, and register with the P2P system. When the user registers with the P2P system the client software is provided with a digital certificate from a server. Once the client software has been provided with the certificate, communication can subsequently be set up and routed between users of the P2P system without the further use of a server. In particular, the users can establish their own communication routes through the P2P system based on the exchange of one or more digital certificates (or user identity certificates, “UIC”), which enable access to the P2P system. The exchange of the digital certificates between users provides proof of the user's identities and that they are suitably authorised and authenticated in the P2P system. Therefore, the presentation of digital certificates provides trust in the identity of the user. It is therefore a characteristic of peer-to-peer communication that the communication is not routed using a server but directly from end-user to end-user. Further details on such a P2P system are disclosed in WO 2005/009019.
One of the advantages of VoIP communication systems, compared to the public switched telephone network (“PSTN”), is that presence information can be provided for the users. Presence information is an indication of the current status of a user of the system. More specifically, presence information is displayed in the user interface of the client for each of the contacts that the user has stored, and allows the user to view the current status of the contacts in the system. Example presence states that may be displayed include “online”, “offline”, “away”, “not available” and “do not disturb”.
The use of presence states provides a user with a best guess regarding the current state of a contact before attempting to communicate with the contact. For example, if the user is not online, and therefore unable to be contacted, then this is indicated to the user before attempting to make a call. Similarly, if a contact is busy and unlikely to answer, then this may also be communicated in advance via the presence state. This is a considerable advantage over PSTN systems, which do not provide any prior information on the probable state of a user. The only option in PSTN systems is to dial a number and wait and see if it is answered.
Presence information in VoIP communication systems can be supplemented by “mood messages”. Mood messages are short text strings that are composed by the users to distribute information about themselves to their contacts and supplement their presence status. The mood message of a contact is generally displayed next to the contact's name and presence status in the client. Mood messages are useful for a number of reasons. For example, a mood message can be used to give more information or a reason for a particular presence status, e.g. if a user is offline, the mood message may say “On holiday”, thereby explaining why the user is offline. Similarly, if a user's presence state is set to “do not disturb”, the mood message may say “Busy working. Only contact me if urgent”. Mood messages are also useful for users that travel frequently, as a VoIP system can be accessed from anywhere in the world, but this is not reflected in the presence states. Therefore, it is useful for a user to show a mood message such as “In London” next to their presence state.
One popular use for mood messages is to incorporate interesting, humorous or entertaining phrases, quotes or slogans. It has been found that users of the VoIP system have readily adopted and enjoy this use of the mood message functionality, as it provides a degree of self-expression and personalisation. Furthermore, users are increasingly using the mood message as a means to easily share some interesting information with all their contacts. For example, users can include a hyperlink to a particular webpage in the mood message, so that all the user's contacts will see the hyperlink and will be prompted to visit the webpage. Similarly, the mood message can be automatically populated by a music player program, so that the mood message displays the title and artist of the music that the user is currently listening to. The use of the mood message as a means of self expression and as a channel to share information can often stimulate conversation over the VoIP system.